Corrosion behavior of two bipolar plate materials in simulated PEMFC environment by electrochemical noise technique

The corrosion behavior of 316L stainless steel (316L) and bulk amorphous Zr75Ti25 (AB) alloy was studied using electrochemical noise (EN) in simulated polymer electrolyte membrane fuel cell (PEMFC) conditions at 25 and 80 degrees C. At open circuit potential, under H-2 environment, AB exhibited a higher corrosion-resistance than 316L and the contrary was observed under O-2 environment. At imposed cathodic potential, under H-2 environment for PEMFC anodic simulation, the reduction mechanism of 316L at 80 degrees C gave the most important EN signals of all other conditions. At imposed anodic potential, under O-2 environment for cathodic simulation, the passive state was observed for 316L while severe localized corrosion for AB was obvious at 80 degrees C. It is concluded from the corrosion data of this work that in the anode environment of a PEMFC, the AB alloy could be a better candidate than 316L for bipolar plates. The contrary was observed in the simulated cathode environment. (c) 2007 Elsevier Ltd. All rights reserved.